Rob Edwards promised that Luton intend to “go down swinging” in their bid to avoid relegation but this was a real sucker punch for his side. Having mounted a stirring comeback thanks to goals from Tahith Chong and Carlton Morris after Ollie Watkins scored twice in the first half, substitute Lucas Digne’s late winner knocked the wind out of Luton’s sails and left the Aston Villa manager, Unai Emery, counting his blessings.

Earlier defeats for Everton and Nottingham Forest had given Luton an opportunity to make up ground in the relegation battle and they could have snatched all three points had Morris made the most of his opportunity with the scores level. But, under Emery, Villa have developed a knack of winning tight games and Digne’s goal after being thrown on as one of four late substitutes ensured they still have a healthy advantage over Tottenham in the race for fourth spot.

Related: Luton Town 2-3 Aston Villa: Premier League – live reaction

“We showed character and mentality to win this game,” admitted Emery. “We knew that Luton would keep coming at us even if we were leading and we couldn’t control the game. But we reacted fantastically with the players we introduced and they helped us to win the game.”

Luton are hoping to start work on a new 17,000 seater stadium in the town centre this year but their current home’s intimidating atmosphere remains one of their most potent weapons. Villa certainly appeared overawed when Morris equalised six minutes after Chong had pulled one back and it seemed like there would only be one winner. But while he could not hide his disappointment after suffering a fifth successive defeat in all competitions, Edwards could take some solace from his team’s battling spirit as they prepare to face several of their relegation rivals here before the end of the season.

“It’s probably the angriest I’ve been this season,” he said of Digne’s goal. “I’ll struggle to sleep tonight but I know that we gave it our best effort against a top team. We have to pick ourselves up and attack the next game.”

Villa could have been out of sight in the first half had it not been for Thomas Kaminski. It took two full length saves from the Luton goalkeeper to keep out efforts from Jacob Ramsey and Watkins before the England striker found space at the near post to head home Leon Bailey’s corner.

The Jamaica winger has nine assists this season and was a constant menace down Villa’s right in the first half. Watkins moved to one goal behind Erling Haaland on 16 for the season – the best return of his career so far – when he latched on to a quick free kick from Douglas Luiz, with VAR confirming that he had timed his run perfectly. “It’s difficult to find a player with a better mentality than him,” said Emery. “He wants to learn every day but is also a very humble person without an ego.”

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Villa picked up where they had left off at the start of the second half but Watkins could not apply the finish when his chance of a hat-trick arrived. It proved to be the turning point as Luton finally woke up, with Chong ending a period of concerted pressure when he stabbed home following a goalmouth scramble that had seen Matty Cash clear the ball off the line. Suddenly Villa looked like the team fighting against relegation.

Luton poured forward and were rewarded again when Morris headed home an Alfie Doughty free-kick, although he could only direct another header at Emilio Martínez minutes later that would have completed the turnaround. But having made four substitutions as he saw the game slipping away, Emery’s gamble paid off when Digne nodded in a cross from another replacement, Moussa Diaby, to allow the Spaniard to pump his fist in celebration at the final whistle.